geothermal power plant projects in central america - Orkustofnun

More documents

Recommendations

Info

9ProductionWellBoiler5Turbine~1046Pre-heater1123RecuperatorInjectionWell7Pumpc2CondenserCooling Tower1c1PumpFIGURE 17: ORC cycle with regeneration schematicThe energy balance equation of boiler can then be determined as (h −h ) = (h −h ) (31)RecuperatorValdimarsson (2011b) concludes that the regeneration process serves only to move the highest powerproduction towards a higher geothermal return temperature; regeneration can help in the case of alower limit on the geothermal fluid temperature imposed by chemistry or by the requirements of asecondary process.The temperature at the turbine outlet is somewhat higher that the condensation temperature. Therefore,this temperature difference can be utilized for heating the working fluid at the entrance to the preheater.The energy balance equation for the recuperator can be described as follows(h −h ) = (h −h ) (32)CondenserFor the binary condenser, the superheated vapor it must be cooled previous to condensation.Therefore, the process has to be divided into two steps. First, cooling the superheated vapor can bedescribed as̅ = (h −h ) (33)21
Second, condensation of the working fluid vapor can be calculated as̅ = (h −h ) (34)where h is the enthalpy of the working fluid in a saturated vapor state, where the pinch point inthe condenser is located. Figure 18 shows the thermodynamic T-s diagram of the process.FIGURE 18: T-s diagram of an ORC cycle (Isopentane) with regeneration4.2 Simulation and optimizationCentral America is a small geographic region divided politically into many territories. There existsimilar economic and climatic conditions for the design of geothermal plants. However, geothermalreservoir and well properties differ from site to site and, as such, require serious attention during thedesign process as they are critical parameters for optimization. In this analysis, power plant models forCentral America were designed based on the technical parameters which do not change from case tocase and on the similar climatic conditions of the region.The methodology applies the fundamental principles of thermodynamics to the components of thecycle and to the cycle itself to form a system of non linear equations as developed in Section 4.1. Theoptimization process was solved by using the mathematical environment called Engineering EquationSolver (EES) which also evaluates thermodynamic properties and solves a system of non linearequations.The optimization process was done over three types of energy conversion systems: single flash (SF),double flash (DF) and organic Rankine cycle (ORC). For each of these cycles design variables andconstraints were defined. The optimization constraints were applied by setting boundaries on eachvariable. In this analysis, the optimization process was carried out on the design variables using adirect search algorithm called the grid search method.According to Rao (2009) the method involves setting up a suitable grid in the design space, evaluatingthe objective function at all the grid points, and the point corresponding to the best objective functionvalue is considered the optimum solution. The power output optimization process was repeated severaltimes in each case for different resource temperatures and mass flows.4.2.1 Assumptions and limitationsSimulation of the models of the energy conversion systems described in Section 4.1 requiredassumptions for a wide range of behavior of the geothermal system and technical characteristics of thepower plant equipment. Table 3 gives a summary of assumptions used as input in this analysis. Someimportant assumptions not used as input for the analysis are:22
Page 1 and 2: GEOTHERMAL TRAINING PROGRAMMEHot sp
Page 3 and 4: This MSc thesis has also been publi
Page 5 and 6: ACKNOWLEDGEMENTSMy gratitude to the
Page 7 and 8: TABLE OF CONTENTSPage1. INTRODUCTIO
Page 9 and 10: PageAPPENDIX A: FINANCIAL MODEL ...
Page 12 and 13: 1. INTRODUCTIONRecent research on r
Page 14 and 15: 2. CENTRAL AMERICAN DATA2.1 Power p
Page 16 and 17: 2.2.3 HondurasThe Honduran electric
Page 18 and 19: NET INJECTION BY SOURCE (2010)INSTA
Page 20 and 21: income taxes for a period of 10 yea
Page 22 and 23: annual temperature ranges from 17 t
Page 24 and 25: egional reconnaissance in 1981ident
Page 26 and 27: 4. GEOTHERMAL ELECTRICAL POWER ASSE
Page 28 and 29: The net contribution of that power
Page 30 and 31: Introducing , = , and , = ,
Page 34 and 35: TABLE 3: Parameters and boundary co
Page 36 and 37: eaches the maximum limit, and for h
Page 38 and 39: 160180140160tc vap[i], th vap[i]120
Page 40 and 41: average results, and combining them
Page 42 and 43: The base cost ( ) can be calculate
Page 44 and 45: calculation for another separator c
Page 46 and 47: mass flow rate (kg/s) on the plant
Page 48 and 49: Table 11 shows a summary of costs f
Page 50 and 51: 5.6.4 Comparison of capital costs b
Page 52 and 53: 6. FINANCIAL FEASIBILITY ASSESSMENT
Page 54 and 55: 6.2 Model structureThe financial fe
Page 56 and 57: CCF = EBITDA − ∆Working Capital
Page 58 and 59: Interest on loansFleischmann (2007)
Page 60 and 61: IRR30%25%IRR CapitalIRR Equity20%Si
Page 62 and 63: FIGURE 42: Allocation of funds for:
Page 64 and 65: 340IRR Free Cash Flow to Equity [ %
Page 66 and 67: flash technology is between 0.3 and
Page 68 and 69: Energy Price Availability Factor O&
Page 70 and 71: FIGURE 50: Density and cumulative p
Page 72 and 73: In Chapter 6, Figure 44 illustrated
Page 74 and 75: The internal rate of return is offs
Page 76 and 77: Cengel, Y. and Tuner, R., 2005: Fun
Page 78 and 79: IEAb, 2011: Technology roadmap: Geo
Page 80 and 81: Salmon, J., Meurice, J., Wobus, N.,
Page 82 and 83:
APPENDIX A: SUMMARY OF FINANCIAL MO
Page 84 and 85:
APPENDIX C: INVESTMENT AND FINANCIN
Page 86 and 87:
APPENDIX E: BALANCE SHEETBALANCE SH
show all

geothermal power plant projects in central america - Orkustofnun

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?